Search results for "LASER"
showing 10 items of 3161 documents
International workshop on next generation gamma-ray source
2022
Journal of physics / G 49(1), 010502 (2022). doi:10.1088/1361-6471/ac2827
Highly efficient isotope separation and ion implantation of 163Ho for the ECHo project
2019
Abstract The effective electron neutrino mass measurement in the framework of the ECHo experiment requires radiochemically pure 163 Ho, which is ion implanted into detector absorbers. To meet the project specifications in efficiency and purity, the entire process chain of ionization, isotope separation , and implantation of 163Ho was optimized. A new two-step resonant laser ionization scheme was established at the 30 kV magnetic mass separator RISIKO. For ionization and separation, an average efficiency of 69 ( 5 ) stat(4)sys% was achieved using intra-cavity frequency doubled Ti:sapphire lasers. The implantation of undesired 166 m Ho, which is present in trace amounts in the initial 163Ho…
Exchange stiffness in the Co2FeSi Heusler compound
2009
Using Brillouin light scattering spectroscopy, we determine the spin-wave exchange stiffness D and the exchange constant A for thin films of the full Heusler compound Co2FeSi prepared by pulsed laser deposition. The thermal spin-wave spectra were measured in various magnetic fields, for different transferred spin-wave momenta, and for different film thicknesses. Fitting the observed spin-wave frequencies, we find an extraordinarily large value of
Q-switching of an all-fiber ring laser based on in-fiber acousto-optic bandpass modulator2017
2017
Active Q-switching of an all-fiber ring laser utilizing a novel in-fiber acousto-optic tunable bandpass filter (AOTBF) is reported. The transmission characteristics of the AOTBF are controlled by amplitude modulation of the acoustic wave; the device exhibits a 3-dB power insertion loss, 0.91-nm optical bandwidth, and 28-dB nonresonant light suppression. Cavity loss modulation is achieved by full acousto-optic mode re-coupling cycle induced by traveling flexural acoustic waves. When the acoustical signal is switched on, cavity losses are reduced, and then, laser emission is generated. In addition, by varying the acoustic wave frequency, a wide wavelength tuning range of 30.7 nm is achieved f…
Opportunities and limitations of in-gas-cell laser spectroscopy of the heaviest elements with RADRIS
2022
International audience; The radiation detection resonance ionization spectroscopy (RADRIS) technique enables laser spectroscopic investigations of the heaviest elements which are produced in atom-at-a-time quantities from fusion-evaporation reactions. To achieve a high efficiency, laser spectroscopy is performed in a buffer-gas environment used to thermalize and stop the high-energy evaporation residues behind the velocity filter SHIP. The required cyclic measurement procedure in combination with the applied filament collection for neutralization as well as confinement of the stopped ions and subsequent pulse-heat desorption constrains the applicability of the technique. Here, some of these…
Developments towards in-gas-jet laser spectroscopy studies of actinium isotopes at LISOL
2015
To study exotic nuclides at the borders of stability with laser ionization and spectroscopy techniques, highest efficiencies in combination with a high spectral resolution are required. These usually opposing requirements are reconciled by applying the in-gas-laser ionization and spectroscopy (IGLIS) technique in the supersonic gas jet produced by a de Laval nozzle installed at the exit of the stopping gas cell. Carrying out laser ionization in the low-temperature and low density supersonic gas jet eliminates pressure broadening, which will significantly improve the spectral resolution. This article presents the required modifications at the Leuven Isotope Separator On-Line (LISOL) facility…
Application of LA-ICP-MS as a rapid tool for analysis of elemental impurities in active pharmaceutical ingredients.
2014
The control of inorganic contaminants in active pharmaceutical ingredients has a significant role in the quality control of drug products. The concentration limits for metal residues in drug products have been defined by various regulatory guidelines. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) is a powerful and fast analytical technique for multi-elemental analysis. A disadvantage in using LA-ICP-MS method is the lack of matrix reference materials for validation and calibration purposes. This article focuses on the handling strategy of laboratory-made matrix calibration standards for the quantification of elemental impurities in an active pharmaceutical ingredie…
Temporal Control of Pulses from a High-Repetition-Rate Tunable Ti:Sapphire Laser by Active Q-switching
2003
We investigated the lasing characteristics of a Ti:sapphire laser pumped by a pulsed high-repetition-rate Nd:YAG laser. The pump laser has a pulsewidth of 450 ns, while the Ti:sapphire laser shows a significantly shorter pulse width of 25 ns for suitably intense pumping. The energy conversion efficiency of the laser is more than 10%. To synchronize different lasers and to avoid multiple spiking during one pump pulse, we use a Brewster-cut Pockels cell in the resonator for Q-switching. The temporal profile and conversion efficiency are determined and compared to theoretical estimates.
Low repetition rate gain-switched double-clad thulium-doped fiber laser operating in the 2 µm wavelength region
2021
Abstract The experimental demonstration of a gain-switched pulsed fiber laser with low repetition rate emission in the 2 µm wavelength region is presented. The laser cavity is based on the figure-9 shape, where the gain-switched operation of the laser is obtained by using a double-clad Tm-doped fiber (DCTDF) as gain medium and a commercial pulsed laser diode at 793-nm with configurable parameters as pump source. The pulse parameters of the pump source are optimized for efficient suppressing of unstable gain-switched laser oscillations. As a result, laser pulses with low repetition rate in a range from 10 to 20 kHz with laser emission at the wavelength of 1951 nm are obtained. The generated …
Surface plasmon-polariton amplifiers
2012
Propagation of surface plasmons at metal surfaces is receiving much interest nowadays because of its broad range of potential applications, like subwavelength photonics or biosensing. Although plasmonic devices achieve unique properties, surface plasmons suffer from high attenuation because of the absorption losses in the metal. This limitation can be overcome by providing the material adjacent to the metal with optical gain. Under these conditions, absorption losses are compensated and the propagation length of the plasmon is significantly increased. In this work, a review of plasmonic amplifiers is presented. To this end, the state of the art of such devices and the propagation characteri…